Bottle cap



July 27, 1943. H. G. VORE 2,325,168

BOTTLE CAP Filed April 30, 1941 INVENTOR ORNEY Patented Jiily 27, 1943UNI-TED STATES IPATENT OFFICE Q 2,325,168' g Herbert G. Vore, JacksonHeights, N. Y., assignor 3 to American Seal-Kap Corporation of Delaware,Wilmington, Del., a corporation of Delaware Application April 30, 1941,Serial rim 391,125

1 Claim. ((31. 215-38) This invention relates to bottle caps and moreparticularly to a partially preformed hood cap for milk bottles or thelike.

An object of the invention is to provide a cap of the above type havingnovel and improved characteristics.

Another object is to provide a hood cap of the above type having apleated skirt, the folds of whichare sealed by a thermoplastic adhesivehaving novel and improved characteristics.

Another object is to provide a hood cap of the type above indicatedhaving a portion of its skirt coated with a thermoplastic adhesive.

Another object is to provide a cap of the above type having athermoplastic adhesive coating which is scalable at a comparatively lowsealing temperature.

Various other objects and advantages will be apparent as the nature ofthe invention is more fully disclosed.

Although the novel features which are believed to be characteristic ofthis invention are pointed out more particularly in the claim appendedhereto, the invention itself may be better understood by referring tothe following description,

taken in connection with the accompanyingdrawing in which a specificembodiment thereof has been set forth for purposes of illustration.

In the drawing, Fig. l is a top plan view the present invention;

Fig. 2 is a side elevation of the cap in position on a milk bottle priorto the sealing operation; Fig. 3 is a side elevation showing thefinished cap in position on the milk bottle with the pleats of a capembodying sealed together; and

Fig. 4 is a diagrammatic View showing the method of applying theadhesive to a stack of caps.

In the following description and in the claim certain specific termshave been used for convenience in referring to various details of theinvention. These terms, however, are to be given as broad aninterpretation as the state of the art will permit.

Referring to the drawing more in detail, the

invention is shown as applied to a cap for a standard milk bottle havinga neck ill, a pouring lip II and an internal ledge i2 adapted to receivea closure disc or the like.

fibrous material which is suflicien'tly stiff and rigid to beself-supporting and moldable for preforming. The paper blank may befirst conditioned and waterproofed by treatment in a wax bath, such, forexample, as a bath of paraffin wax having a suitable anti-oxidant toprevent the bath from oxidizing after long continued use. The blank maybe first moistened and then immersed in the wax bath at a temperaturesuited to drive off the moisture and cause the wax to be absorbed intothe fibres. After a suitable treatment-of the above type, the blanks maybe removed from the wax bath, cooled and stored for a suflicient periodof time to cause the wax to set or to be uniformly distributed throughthe fibres. The blank as thus formed is waterresistant and issufficiently pliable for the forming operation to be described. It is tobe understood, however, that the conditioning of the blank abovementioned forms no part of the present invention and that the blank maybe conditioned by other suitable processes. j. i

The conditioned blanks are then partially preformed in a suitableforming press to provide a central ,bore closing portion i5 adapted toseat within the pouring lip l l of the bottle cap on the internal ledgel2 thereof, a U-shaped pouring lip housing I6 joined to the centralbore-closing portion !5 and adapted to cover the pouring, lip

of the bottle II, and an outer flared depending skirt H.

The skirt I1 is formed with a plurality of folds or pleats i8 whichextend outwardly beyond the pouring lip housingi6 and are adapted to befolded downwardly around the outer surface of closing portion -of thecap on the ledge i2 of the bottle.

In order to secure the folds or pleats I8 to each other, I provide athermoplastic adhesive coating of the type hereinafter specified. Thiscoating may be applied to-the entire cap or to the blank if desired. Iprefer, however, to apply the coating only to a portion of the outersurface of the cap skirt, for example, as an annular band around the'lower portion; of said skirt;

' The coating is preferably of the type which will only adhere toanother surface having the same coating so that .the pleats, when foldedover, will adhere together but will not adhere to the glass of thebottle or to an uncoated surface such asthe skirt of another cap. Bythus The entire surface of the skirt Il may, of

course, becoated. Iprefer, however, to apply '-'the coating only in theform of a band around the exposed edge thereof. This facilitates thehandling of the cap and also reduces the quantity of adhesive which isrequired.

In accordance with my invention, I propose to apply the adhesive in theform of a spray to the exposed portions of the skirts of the stack ofcaps as shown in Fig. 4. For this purpose, the caps are stacked andnested with the pleats in substantial registration'and with the line ofnested pleats extending helically around the stack of caps, as indicatedby the line A--'A of Fig. 4. I then support the stack of cops bysuitable means shown as pins 25 and rotate the same rapidly about theiraxis in the direction of the exposed fold 26 between adjacent pleats, asindicated by the arrow in Fig. 4;

While the stack of caps is ply the adhesive thereto in the form of aspray as, for example, from a nozzle 21. The nozzle 21 is preferably sodesigned that the spray 28 fans out in the shape of a thin extendedlayer.

In coating the skirt the nozzle 21 may be moved longitudinally of therotating stack of caps either manually or by suitable mechanical meansnot shown. During this movement the nozzle should be maintained in aposition such that the spray is applied in a direction about normal tothe face of skirts II as, for example, an angle indicated by theinclination of the pipe 30 of Fig. 4. At the same time the spray shouldbe positioned to enter into the folds 26 between adjacent pleats tionconsisting of Pliolite 100 parts, paraflin wax 12% parts andhydrogenated rosin (staybelite) 25 parts. This mixture is completelystable and has the property of softening at a low temperature, yet it issufliciently hard at room temperature to prevent the caps from becomingsticky and thereby interfering with the handling or thus rotating, I ap-I8 of the skirt and with the plane of the spray 28 extendingsubstantially parallel to the line AA of the nested pleats. In this waythe spray is driven into the folds as the stack of caps is rotated andis caused to adhere particularly to the portions of the cap which are tobe folded over for securing the same. The spray also forms a band 3i ofadhesive extending completely around the lower portion of the outersurface of the skirt of the cap.

The nozzle should be held normal to the surface of the pleats so as toprevent the spray from being driven upbetween the stacked skirts andthereby tending to cause adjoining caps to stick together and in orderto prevent the liquid from running from one skirt to the next andforming an adhesive film therebetween. It is to be understood, however,that the angle of the spray and the direction of rotation of the capsmay be varied in accordance with the particular adhesive used and withthe particular requirements of any specific case.

In order to facilitate the subsequent heat sealing of the caps, I preferto use a thermoplastic adhesive having a low sealing temperature so thatit can be readily softened by the application of a slight amount of heatand is permanently sealed by heat and pressure. I have found thatisomerized rubber (Pliolite) or Pliolite'and rubber are particularlysuited for the above purpose. Various other adhesives having similarproperties, such as chlorinated rubber and polybutenes may also beemployed.

The adhesive may be dissolved in a suitable solvent and may, if desired,have a dye incorposhipping thereof.

This composition may be dissolved in a suitable solvent, which is also asolvent for paraflin wax so that when applied to the wax treated capsthe solvent dissolves away a suflicient portion of the paraffin waxcoating from the surface of the cap to permit the adhesive to becomefirmly bonded thereto.

I have found that a petroleum distillate boiling between 150 F. and 200F. possesses these characteristics. Such a distillate may compriseprincipally hexane together with various other constituents. Variousother solvents may be used, however, such, for'example, as benzene,carbon tetrachloride, toluene and the like.

A suitable anti-oxidant should be added to the above composition toprevent the composition from losing its heatsealing properties as theresult of oxidation. Such an anti-oxidant may comprise, for example,tannic acid, hydroquinone, aniline, acetaldehyde or other well knownrubber anti-oxidant.

If a colored dye is desired various non-toxic dyesimay be added to thecomposition. Examples of such dyes are the following:

Sudanyellow--aniline azo-B-naphthol Sudanred-aminoazobenzeneazoB-naphthol Aniline black-nigrosine ,Tartrazine--a yellow pyrazolone dyesuited to use with a standard spray nozzle.

After a stack of caps has been treated as above indicated, to spray afilm of adhesive to the lower portions of the overlapped skirts, thematerial may be allowed'to set and then, if desired, the stack of capsmay be squeezed together endwise so as to reduce the over-all dimensionof the stack and also to break any bond which may have been formedbetween adjacent caps. In this way the caps in the stack are completelyseparated and adapted to be fed to a suitable capping head. The caps maybe shipped in this form and in the dairy may be applied to the bottlesand heat sealed to form a finished cap of the type,v shown in Fig. 3.

Although a specific embodiment of the invention has been set forth' forpurposes of illustration, it is to be understood that various changesand alterations may be made therein as will be apparent to a. personskilled in the art. The in the outer surface of the pouring lip of thebottle,

at least the skirt portion of said cap having a, poating comprisingisomerized rubber, para emmas and a. hydrogenated rosin havin gthermoplastic properties, in about the following proportion? PartsIsomerized rubber 14% 5 Parafin wax 12 Hydrogenated rosin 25 IIERBERT G.VORE.

